Answer:
x = 9±sqrt(7)
Step-by-step explanation:
3(x-9)^2 =21
Divide each side by 3
3/3(x-9)^2 =21/3
(x-9)^2 =7
Take the square root of each side
sqrt((x-9)^2) =±sqrt(7)
x-9 =±sqrt(7)
Add 9 to each side
x = 9±sqrt(7)
The launchers height above the ground at zero distance h(x)+0+0+.4= 4 meaning that the height is 4 <span />
Total number of seats = 5
Total number of friends = 5
We want to find in how many ways the 5 friends can sit or be arranged in 5 seats. This can be found using permutations.So we are to find the permutations of 5 objects taken 5 at a time. This can be expressed as 5P5.
5P5 = 120
So, the 5 friends can sit in 120 different ways.
The correct answer is option D
